Increased efficiency fractional distillation tray

Abstract

The efficiency of multiple down comer fractional distillation trays is improved by distributing the liquid egressing from the bottom of the downcomers in a manner which provides a uniform length liquid flow path on the next lower tray. This is accomplished by liquid distribution devices suspended below the downcomers of the upper tray, with the devices running parallel to the downcomers of the next lower tray and being adapted to collect the falling liquid and then disperse it onto the decking below along the length of the lower downcomers through openings in the distribution device.

What is claimed:  
     
       1. An apparatus for performing fractional distillation in a fractionation column, the apparatus comprising: 
       an upper first tray and a lower second tray, with both the first and second trays comprising a trough-like downcomer and vapor-liquid decking panels adjacent the downcomer and having at least two groups of liquid outlets in the bottom of the downcomer; and  
       a liquid collection and distribution device mounted at an intermediate level between the downcomer of the first tray and the decking of the second tray, the liquid collection and distribution device being of sufficient length to receive liquid falling from at least two groups of downcomer liquid outlets of the first tray and having at least one row of liquid outlets aligned parallel with the downcomer of the second tray, whereby liquid from the first tray falling into the liquid collection and distribution device is distributed across a decking panel of the lower second tray at a uniform distance from the downcomer adjacent to the decking panel.  
     
     
       2. The apparatus of  claim 1  wherein the number of liquid collection and distribution devices per tray is one greater than the number of downcomers per tray. 
     
     
       3. The apparatus of  claim 1  further characterized in that a bridge piece is affixed across an open mouth of the liquid collection and distribution device below the downcomer liquid outlets. 
     
     
       4. The apparatus of  claim 1  wherein two sidewalls extend the length of the liquid collection and distribution device. 
     
     
       5. The apparatus of  claim 4  wherein the sidewalls are planar. 
     
     
       6. The apparatus of  claim 4  further comprising spaced-apart liquid catching wing tabs, said wing tabs extending outward from the liquid collection and distribution device at the top edge of the sidewalls of the device. 
     
     
       7. The apparatus of  claim 1  wherein the liquid collection and distribution device is supported by stanchions attached to the second tray. 
     
     
       8. The apparatus of  claim 1  wherein the downcomer of the first tray is oriented differently than the downcomer of the second tray. 
     
     
       9. The apparatus of  claim 1  wherein the liquid collection and distribution device is supported by attachment to at least two downcomers. 
     
     
       10. An apparatus for performing fractional distillation in a fractionation column, the apparatus comprising: 
       an upper first tray and a lower second tray, with both the first and second trays comprising at least two trough-shaped downcomers and at least one vapor-liquid decking panel located between the downcomers, and with the downcomers of the first tray being oriented differently than the downcomers of the second tray, with the downcomers of each tray having at least two groups of spaced apart liquid outlets in the bottom of the downcomer; and  
       at least two liquid collection and distribution devices mounted between the bottom of the downcomers of the first tray and the top of the vapor-liquid decking panel of the second tray, the liquid collection and distribution devices being of length sufficient to receive liquid falling from the liquid outlets of at least two downcomers of the first tray, with the liquid collection and distribution devices being aligned parallel with the downcomers of the second tray and having liquid outlets aligned parallel with the downcomers of the second tray and above the decking of the second tray to deposit liquid onto the decking of the second tray at uniform distances from the downcomers of the second tray.  
     
     
       11. The apparatus of  claim 10  wherein the downcomers of the first tray are oriented transverse to the downcomers of the second tray.